The present invention relates to apparatus and methods and particularly, but not exclusively, to an expander device and method for expanding an internal diameter of a casing, pipeline, conduit or the like. The present invention also relates to a tubular member such as a casing, pipeline, conduit or the like.
A borehole is conventionally drilled during the recovery of hydrocarbons from a well, the borehole typically being lined with a casing. Casings are installed to prevent the formation around the borehole from collapsing. In addition, casings prevent unwanted fluids from the surrounding formation from flowing into the borehole, and similarly, prevent fluids from within the borehole escaping into the surrounding formation.
Boreholes are conventionally drilled and cased in a cascaded manner; that is, casing of the borehole begins at the top of the well with a relatively large outer diameter casing. Subsequent casing of a smaller diameter is passed through the inner diameter of the casing above, and thus the outer diameter of the subsequent casing is limited by the inner diameter of the preceding casing. Thus, the casings are cascaded with the diameters of the successive casings reducing as the depth of the well increases. This successive reduction in diameter results in a casing with a relatively small inside diameter near the bottom of the well that could limit the amount of hydrocarbons that can be recovered. In addition, the relatively large diameter borehole at the top of the well involves increased costs due to the large drill bits required, heavy equipment for handling the larger casing, and increased volumes of drill fluid which are required.
Each casing is typically cemented into place by filling an annulus created between the casing and the surrounding formation with cement. A thin slurry cement is pumped down into the casing followed by a rubber plug on top of the cement. Thereafter, drilling fluid is pumped down the casing above the cement that is pushed out of the bottom of the casing and into the annulus. Pumping of drilling fluid is stopped when the plug reaches the bottom of the casing and the wellbore must be left, typically for several hours, whilst the cement dries. This operation requires an increase in drill time due to the cement pumping and hardening process, which can substantially increase production costs.
To overcome the associated problems of cementing casings and the gradual reduction in diameters thereof, it is known to use a more pliable casing that can be radially expanded so that an outer surface of the casing contacts the formation around the borehole. The pliable casing undergoes plastic deformation when expanded, typically by passing an expander device, such as a ceramic or steel cone or the like, through the casing. The expander device is propelled along the casing in a similar manner to a pipeline pig and may be pushed (using fluid pressure for example) or pulled (using drill pipe, rods, coiled tubing, a wireline or the like).
Additionally, a rubber material or other high friction coating is often applied to selected portions of the outer surface of the unexpanded casing to increase the grip of the expanded casing on the formation surrounding the borehole or previously installed casing. However, when the casing is being run-in, the rubber material on the outer surface is often abraded during the process, particularly if the borehole is highly deviated, thereby destroying the desired objective.
According to a first aspect of the present invention there is provided a tubular member for a wellbore, the tubular member including coupling means to facilitate coupling of the tubular member into a string, the coupling means being disposed on an annular shoulder provided at at least one end of the tubular member, the tubular member further including at least one recess wherein a friction and/or sealing material is located within the recess.
Typically, the tubular member is a casing, pipeline, conduit or the like. The tubular member may be of any length, including a pup joint.
The at least one recess is preferably an annular recess.
The at least one recess is typically weakened to facilitate plastic deformation of the at least one recess. Heat is typically used to weaken the at least one recess.
The internal diameter of the at least one recess is typically reduced with respect to the internal diameter of the tubular member adjacent the recess. The internal diameter of the at least one recess is typically reduced by a multiple of a wall thickness of the tubular member. The internal diameter of the at least one recess is preferably reduced by an amount between 0.5 and 5 times the wall thickness, and most preferably by an amount between 0.5 and 2 times the wall thickness. Values outside of these ranges may also be used.
Preferably, the coupling means is disposed on an annular shoulder provided at each end of the tubular member. The coupling means typically comprises a threaded coupling. A first screw thread is typically provided on the annular shoulder at a first end of the tubular member, and a second screw thread is typically provided on the annular shoulder at a second end of the tubular member. The coupling means typically comprises a pin connection on one end and a box connection on the other end. Thus, a casing string or the like can be created by threadedly coupling successive lengths of tubular member.
The inner diameter of the annular shoulder is typically enlarged with respect to the inner diameter of the tubular member adjacent the annular shoulder. The inner diameter of the annular shoulder is typically increased by a multiple of a wall thickness of the tubular member. The inner diameter of the annular shoulder is preferably enlarged by an amount between 0.5 and 5 times the wall thickness, and most preferably enlarged by an amount between 0.5 and 2 times the wall thickness. Values outside of these ranges may also be used.
The tubular member is preferably manufactured from a ductile material. Thus, the tubular member is capable of sustaining plastic deformation.
According to a second aspect of the present invention there is provided an expander device comprising a body provided with a first annular shoulder, and a second annular shoulder spaced apart from the first annular shoulder.
The expander device is typically used to expand the diameter of a tubular member such as a casing, pipeline, conduit or the like.
The radial expansion of the second annular shoulder is preferably greater than the radial expansion of the first annular shoulder.
The expander device is preferably used to expand a tubular member, the tubular member including coupling means to facilitate coupling of the tubular member into a string, the coupling means being disposed on an annular shoulder provided at at least one end of the tubular member, the tubular member further including at least one recess wherein a friction and/or sealing material is located within the recess.
The second annular shoulder is preferably spaced apart from the first annular shoulder by a distance substantially equal to the distance between an annular shoulder of a preceding tubular member (when coupled together into a string) and the at least one recess of the tubular member. Preferably, the first annular shoulder of the expander device contacts the at least one recess of the tubular member substantially simultaneously with the second annular shoulder of the expander device entering an annular shoulder of the tubular member. The force required to expand the annular shoulder of the tubular member is significantly less than the force required to expand the nominal inner diameter portions of the tubular member. Thus, as the second annular shoulder of the expander device enters the annular shoulder of the tubular member, the force required to expand the nominal inner diameter portions of the tubular member is not required to expand the annular shoulders of the tubular member and the difference in force facilitates an increase in the force which is required to expand the diameter of the at least one recess.
The expander device is typically manufactured from steel. Alternatively, the expander device may be manufactured from ceramic, or a combination of steel and ceramic. The expander device is optionally flexible.
The expander device is optionally provided with at least one seal. The seal typically comprises at least one O-ring.
The expander device is typically propelled through the tubular member, pipeline, conduit or the like using fluid pressure. Alternatively, the device may be pigged along the tubular member or the like using a conventional pig or tractor. The device may also be propelled using a weight (from the string for example), or may be pulled through the tubular member or the like (using drill pipe, rods, coiled tubing, a wireline or the like).
According to a third aspect of the present invention, there is provided a method of lining a borehole in an underground formation, the method comprising the steps of lowering a tubular member into the borehole, the tubular member including coupling means to facilitate coupling of the tubular member into a string, the coupling means being disposed on an annular shoulder provided at at least one end of the tubular member, the tubular member further including at least one recess wherein a friction and/or sealing material is located within the recess, and applying a radial force to the tubular member using an expander device to induce a radial deformation of the tubular member and/or the underground formation.
The expander device preferably comprises a body provided with a first annular shoulder, and a second annular shoulder spaced apart from the first annular shoulder.
The method typically includes the further step of removing the radial force from the tubular member.
The tubular member is preferably manufactured from a ductile material. Thus, the tubular member is capable of sustaining plastic deformation.
The at least one recess is preferably an annular recess.
The at least one recess is typically weakened to facilitate plastic deformation of the at least one recess. Heat is typically used to weaken the at least one recess.
The friction and/or sealing material is typically located within the at least one recess when the tubular member is unexpanded. The friction and/or sealing material typically becomes proud of the outer surface adjacent the at least one recess of the tubular member when the at least one recess is expanded by the first annular shoulder on the expander device. The friction and/or sealing material typically becomes proud of the outer surface of the tubular member when the at least one recess is expanded by the second annular shoulder on the expander device.
The internal diameter of the at least one recess is typically reduced with respect to the internal diameter of the tubular member adjacent the recess. The internal diameter of the at least one recess is typically reduced by a multiple of a wall thickness of the tubular member. The internal diameter of the at least one recess is preferably reduced by an amount between 0.5 and 5 times the wall thickness, and most preferably reduced by an amount between 0.5 and 2 times the wall thickness. Values outside of these ranges may also be used.
Preferably, the coupling means is disposed on an annular shoulder provided at at least one end of the tubular member. The coupling means typically comprises a threaded coupling. A first screw thread is typically provided on the annular shoulder at a first end of the tubular member, and a second screw thread is typically provided on the annular shoulder at a second end of the tubular member. The coupling means typically comprises a pin connection on one end and a box connection on the other end. Thus, a tubular member string can be created by threadedly coupling successive lengths of tubular member.
The inner diameter of the annular shoulder is typically enlarged with respect to the inner diameter of the tubular member adjacent the annular shoulder. The inner diameter of the annular shoulder is typically increased by a multiple of a wall thickness of the tubular member. The inner diameter of the annular shoulder is preferably enlarged by an amount between 0.5 and 5 times the wall thickness, and most preferably enlarged by an amount between 0.5 and 2 times the wall thickness. Values outside of these ranges may also be used.
The tubular member is preferably manufactured from a ductile material. Thus, the tubular member is capable of sustaining plastic deformation.
The expander device is typically used to expand the diameter of the tubular member, pipeline, conduit or the like.
The radial expansion of the second annular shoulder is preferably greater than the radial expansion of the first annular shoulder.
The expander device is preferably used to expand a tubular member, the tubular member including coupling means to facilitate coupling of the tubular member into a string, the coupling means being disposed on an annular shoulder provided at at least one end of the tubular member, the tubular member further including at least one recess wherein a friction and/or sealing material is located within the recess.
The second annular shoulder is preferably spaced apart from the first annular shoulder by a distance substantially equal to the distance between the annular shoulder and the at least one recess of the tubular member. Preferably, the first annular shoulder of the expander device contacts the at least one recess of the tubular member substantially simultaneously with the second annular shoulder of the expander device entering an annular shoulder of the tubular member. The force required to expand the annular shoulder of the tubular member is significantly less than the force required to expand the nominal inner diameter portions of the tubular member. Thus, as the second annular shoulder of the expander device enters the annular shoulder of the tubular member, the force required to expand the nominal inner diameter portions of the tubular member is not required to expand the annular shoulders of the tubular member and the difference in force facilitates an increase in the force which is required to expand the diameter of the at least one recess.
The expander device is typically manufactured from steel. Alternatively, the expander device may be manufactured from ceramic, or a combination of steel and ceramic. The expander device is optionally flexible.
The expander device is optionally provided with at least one seal. The seal typically comprises at least one O-ring.
The expander device is typically propelled through the tubular member, pipeline, tubular or the like using fluid pressure. Alternatively, the device may be pigged along the tubular member or the like using a conventional pig or tractor. The device may also be propelled using a weight (from the string for example), or may be pulled through the tubular member or the like (using drill pipe, rods, coiled tubing, a wireline or the like).
According to a fourth aspect of the present invention there is provided a tubular member for a wellbore, the tubular member including a friction and/or sealing material applied to an outer surface of the tubular member, the friction and/or sealing material being disposed on a protected portion so that the friction and/or sealing material is substantially protected whilst the tubular member is being run into the wellbore.
Typically, the tubular member is a casing, pipeline, conduit or the like. The tubular member may be of any length, including a pup joint.
The protected portion typically comprises a valley located between two shoulders. The valley is typically of the same inner diameter as the tubular member. The shoulders typically have an inner diameter that is typically increased by a multiple of a wall thickness of the tubular member. The inner diameter of the shoulder is preferably enlarged by an amount between 0.5 and 5 times the wall thickness, and most preferably enlarged by an amount between 0.5 and 2 times the wall thickness. Values outside of these ranges may also be used. The shoulders typically comprise annular shoulders. The valley typically comprises an annular valley.
Alternatively, the protected portion may comprise a cylindrical portion located substantially adjacent a shoulder portion, wherein the outer diameter of the shoulder portion is preferably of a greater diameter than the outer diameter of the cylindrical portion. The shoulder is preferably located so that the cylindrical portion is substantially protected whilst the tubular member is being run into the wellbore. Thus, the friction and/or sealing material is substantially protected by the shoulder whilst the member is being run into the wellbore. The cylindrical portion is typically of the same inner diameter as the tubular member. The shoulder typically has an inner diameter that is typically increased by a multiple of a wall thickness of the tubular member. The inner diameter of the shoulder is preferably enlarged by an amount between 0.5 and 5 times the wall thickness, and most preferably enlarged by an amount between 0.5 and 2 times the wall thickness. Values outside of these ranges may also be used.
The protected portion may alternatively comprise a recess in the outer diameter of the tubular member. The recess may be machined, for example, or may be swaged. The friction and/or sealing material is typically located within said recess. In these embodiments, the outer diameter of the tubular member remains substantially the same over the length of the member, as the friction and/or sealing material is located within the recess.
Typically, the tubular member includes coupling means to facilitate coupling of the tubular member into a string. Alternatively, the lengths of tubular member may be welded together or coupled in any other conventional manner.
The coupling means is typically disposed at each end of the tubular member. The coupling means typically comprises a threaded coupling. The coupling means typically comprises a pin on one end of the tubular member, and a box on the other end of the tubular member. Thus, a casing string or the like can be created by threadedly coupling successive lengths of tubular member.
The tubular member is preferably manufactured from a ductile material. Thus, the tubular member is capable of sustaining plastic deformation.